Want to learn about DF kernel

[elekktretterr at exemail.com.au]

Hi,

I've got some free time now as I quit my job, so I would like to learn
about kernel hacking. I'd like to start by ripping out DragonFly's USB
stack, in preparation for import of FreeBSD's.

Can anyone describe what the steps that need to be done to take out our
old USB stack, and also the files and directories involved. That would be
really helpful.

Cheers...